Locked out at home is one of the most common calls we get — a door that locked behind you, a lost or broken key, or a lock that's simply seized up. Entry is non-destructive in the large majority of cases: picking or bypassing the existing lock rather than drilling, so your hardware survives the visit.
Rekeying is different from replacing a lock — the cylinder inside is refitted to work with a new key while the hardware on your door stays the same, which is why it's the standard move after a move-in, a lost key, or handing back a key you'd rather not have floating around. One key can often be cut to work across all your exterior doors.
Photo ID matching the address, or another way to confirm residency (mail, a neighbour who can vouch, a landlord's confirmation for tenants). This protects you — it's the same check that stops someone else from locking you out for good.
Yes — that's exactly what rekeying is. The existing hardware stays; only the internal pins change to match a new key.
As many as you need, cut on the spot in most cases. Many clients rekey all exterior doors to one master key for convenience.
Don't try to dig it out with pliers or superglue (we see this go wrong constantly) — call for extraction. Most broken keys come out clean without damaging the cylinder.